“A scanning probe microscope” is a general term for a microscope by which a sample is examined by scanning the very close vicinity of the sample using a sharp pointed probe, typical one being known as an atomic force microscope. As an atomic force microscope, the one equipped with a cantilever with a tip curved like a hook and which tip is used as a probe is known. The surface shape of a sample is observed by measuring the displacement of the cantilever which is based on the interatomic force between the sample and the tip of the probe.
A scanning probe microscope is also known which has functions of an atomic force microscope and an near-field optical microscope at the same time by forming the cantilever and probe for such an atomic force microscope with a light transmitting substrate, by coating the probe except for the tip of the probe or including the tip of the probe with a metal layer, and by using the probe as a probe of the near-field optical microscope (Patent Literature 1). That is, when a laser beam is guided through the cantilever to the tip of the probe, an evanescent light is radiated from the tip of the probe. And, for example, a fluorescence labeled sample or the like is excited by this evanescent light to emit fluorescence, and the sample can be observed optically by detecting the emitted fluorescence. In this way, by using the microscope having functions of an atomic force microscope and an near-field optical microscope at the same time, the shape of a sample can be observed by the atomic force microscope, as well as a wide variety of fluorescence labeled substances can be observed. Therefore, by observing a cell by using the microscope, for example, a minute shape of the cell and the intracellular distribution of fluorescent labeled calcium ion, potassium ion, magnesium ion and the like can be observed at the same time.
On the other hand, co-inventors of the present invention invented a method of forming a very small electrode by electrodepositing resin covering on the whole surface of the metal layer using a metal layer which was formed on a pointed optical fiber beforehand as an electrode and by exposing the metal layer under the resin covering by shrinking the resin covering by heating to break the tip of the resin covering (Patent Literature 2).    Patent Literature 1: JP 2704601 B    Patent Literature 2: JP 2004-45394 A    Patent Literature 3: JP 2001-208671 A    Patent Literature 4: JP 3264824 B    Patent Literature 5: JP H9-89911 A    Patent Literature 6: JP H11-51943 A